Using Zip Code Data Using Zip Code Data in Community College in Community College Enrollment AnalysisEnrollment Analysis

AIR 2005, San DiegoAIR 2005, San Diego

Willard Hom, System Office, CCCWillard Hom, System Office, CCC

Terrence Willett, Gavilan CollegeTerrence Willett, Gavilan College

PrefacePreface

The System Office, CCC, has the zip The System Office, CCC, has the zip code of residence for every student who code of residence for every student who attends a California community college.attends a California community college.

A community college/district may A community college/district may request a data file on students, request a data file on students, according to a specified set of zip according to a specified set of zip codes.codes.

We present an application of such zip We present an application of such zip code data that can help local planning code data that can help local planning efforts.efforts.

Analytical Uses of Zip Analytical Uses of Zip Code DataCode Data

Definition of politically defined Definition of politically defined service population.service population.

Estimation of “inflow”---students Estimation of “inflow”---students from areas outside the district’s from areas outside the district’s designated area.designated area.

Estimation of “outflow”—students Estimation of “outflow”—students who reside in the district’s area but who reside in the district’s area but who attend a different CC district.who attend a different CC district.

Politically Defined Politically Defined Service PopulationService Population

District’s base population for District’s base population for indicators of performance and equity indicators of performance and equity (i.e., participation rates).(i.e., participation rates).

District’s political basis for local District’s political basis for local funding.funding.

District’s basis for state budgeting.District’s basis for state budgeting.

Inflow and Outflow Inflow and Outflow implicationsimplications

Inflow may indicate:Inflow may indicate: Strengths in a districtStrengths in a district

Perceived or actual high quality programs, services, Perceived or actual high quality programs, services, facilitiesfacilities

Draw with distance learningDraw with distance learning Relative competitive weaknesses in “sending” Relative competitive weaknesses in “sending”

areasareas Multi-area routine due to traffic patternsMulti-area routine due to traffic patterns

Outflow may indicate:Outflow may indicate: Room for improvement in a districtRoom for improvement in a district

Perceived or actual low quality of programs, services, Perceived or actual low quality of programs, services, facilitiesfacilities

Relative competitive strengths in “sending” areasRelative competitive strengths in “sending” areas Multi-area routine due to traffic patternsMulti-area routine due to traffic patterns

Cross-sectional AnalysisCross-sectional Analysis

Gives snapshot of a district’s market.Gives snapshot of a district’s market. Need measurement of variables at Need measurement of variables at

only one point in time (less only one point in time (less demanding than panel analysis).demanding than panel analysis).

Can be a first phase of a panel Can be a first phase of a panel analysis.analysis.

Cross-sectional Outcome Cross-sectional Outcome GroupsGroups

Movers = High Concern

Concurrent = Some Concern

Stayers = Less Concern

Panel AnalysisPanel Analysis Do students transition to movers in stages, Do students transition to movers in stages,

going from stayer, or concurrent, to going from stayer, or concurrent, to mover?mover?

Can capture the “effect” of an event to Can capture the “effect” of an event to some extent (depending on confounding some extent (depending on confounding factors).factors).

Is necessary for noting any trend.Is necessary for noting any trend. Demands more inputs (and time) than Demands more inputs (and time) than

cross-sectional analysis.cross-sectional analysis. Can be an extension of an old cross-Can be an extension of an old cross-

sectional analysis.sectional analysis.

Panel Analysis Outcome Panel Analysis Outcome GroupsGroupsTime 2Time 2

Your CollegeYour College Other Other CollegeCollege

Time Time 11

Your Your CollegeCollege

In StayerIn Stayer OutflowOutflow

Other Other CollegeCollege

InflowInflow Out StayerOut Stayer

Each additional time period is another dimension.

Decision Factors for Decision Factors for Outflow (or Inflow)Outflow (or Inflow)

Multi-area lifestyle (i.e., commute to work).Multi-area lifestyle (i.e., commute to work). Other travel factors (time, cost, ease, Other travel factors (time, cost, ease,

safety, etc.)safety, etc.) Curriculum differences.Curriculum differences. Special activities (i.e. athletics)Special activities (i.e. athletics) Perception of transfer opportunity.Perception of transfer opportunity. Distance learning options.Distance learning options. Perceived differences in campus Perceived differences in campus

climate/culture.climate/culture.

Reasons to Test the Reasons to Test the Forces for Flow (In or Forces for Flow (In or

Out)Out) To identify areas where a district To identify areas where a district

may improve its service/product.may improve its service/product. To identify areas where a district To identify areas where a district

may need to change students’ may need to change students’ perceptions.perceptions.

To identify situations where the To identify situations where the costs of remediation are excessive or costs of remediation are excessive or futile.futile.

The Descriptive-The Descriptive-Explanatory ContinuumExplanatory Continuum

DescriptiveHow many stay or go?

ExplanatoryWhy do they stay or go?1-way tabs

2-way c/s tabs

n-way panel tabs

logistic regression/CART

Basic Model of Basic Model of Enrollment ChoiceEnrollment Choice

student values

student perceptions

Attend District CC

(or not)actual

conditions

Stay in district or leave district

Overall Strategy for Overall Strategy for ChangeChange

marketing

program change conditions

perceptions

student choice

The Case of GavilanThe Case of Gavilan

_̂

_̂Gavilan Antipodal Point

Gavilan College Main Campus

Gavilan College Main Campus and its Anitpodal Point

µ0 15,000 30,0007,500 Kilometers

Gavilan Research Office 2004

_̂

!(

!(

!(

!(

!(

!(

!(

!(Gavilan College

Orick

Amboy

Mariposa

San Diego

Santa Cruz

Sacramento

Los Angeles

San Francisco

Gavilan’s Free FlowGavilan’s Free Flow

   HeadcountHeadcount UnitsUnits

   Gavilan Gavilan Not Not

GavilanGavilan Gavilan Gavilan Not Not

GavilanGavilan

Fall Fall 20012001 69%69% 31%31% 6.96.9 6.36.3

Fall Fall 20022002 69%69% 31%31% 7.27.2 6.16.1

Fall Fall 20032003 67%67% 33%33% 7.57.5 6.46.4

MeanMean 68%68% 32%32% 7.27.2 6.26.2

Univariate GinsuUnivariate Ginsu In general, it appears that students who In general, it appears that students who

live in our district but go to community live in our district but go to community colleges elsewhere are:colleges elsewhere are: more likely to live closer to San Jose more likely to live closer to San Jose of a similar age distribution to those who come of a similar age distribution to those who come

to Gavilan except leavers have relatively fewer to Gavilan except leavers have relatively fewer members over 60 members over 60

more likely to be male and non-Hispanic more likely to be male and non-Hispanic more likely to have a high school diploma or an more likely to have a high school diploma or an

AA (those with no diploma or a BA or higher are AA (those with no diploma or a BA or higher are more likely to come to Gavilan)more likely to come to Gavilan)

less likely to take as many unitsless likely to take as many units more likely to be enrolled in vocational type more likely to be enrolled in vocational type

programs that are mostly not transferable.programs that are mostly not transferable.

   Enrollment Enrollment

Count Count Enrollment Enrollment

Percent Percent

TOP nameTOP name

GavilGavilan an

Not Not Gavilan Gavilan

GavilGavilan an

Not Not Gav Gav

Agriculture and Agriculture and Natural ResourcesNatural Resources 00 399399 0%0% 100%100%

LawLaw 00 109109 0%0% 100%100%

Architecture and Architecture and Environmental Environmental DesignDesign

00 5757 0%0% 100%100%

Military StudiesMilitary Studies 00 1212 0%0% 100%100%

Library ScienceLibrary Science 1111 141141 7%7% 93%93%

   Enrollment Enrollment

Count Count Enrollment Enrollment

Percent Percent

TOP nameTOP name Gavilan Gavilan Not Not Gavilan Gavilan Gavilan Gavilan Not Gav Not Gav

Public and Public and Protective Protective ServicesServices

18421842 95999599 16%16% 84%84%

Engineering Engineering and Industrial and Industrial TechnologiesTechnologies

777777 14071407 36%36% 64%64%

MathematicsMathematics 28342834 19341934 59%59% 41%41%

HealthHealth 16241624 10041004 62%62% 38%38%

Physical Physical SciencesSciences 21552155 10321032 68%68% 32%32%

EducationEducation 52685268 23322332 69%69% 31%31%

Family and Family and Consumer Consumer SciencesSciences

37633763 16561656 69%69% 31%31%

   Enrollment Count Enrollment Count Enrollment Percent Enrollment Percent

TopnameTopname Gavilan Gavilan

Not Not Gavilan Gavilan Gavilan Gavilan Not Gav Not Gav

Foreign Foreign LanguageLanguage 20152015 791791 72%72% 28%28%

Information Information TechnologyTechnology 27332733 810810 77%77% 23%23%

Social Social SciencesSciences 91199119 25852585 78%78% 22%22%

Media and Media and CommunicatiCommunicationsons

212212 5656 79%79% 21%21%

Humanities Humanities (Letters)(Letters) 1879818798 47674767 80%80% 20%20%

PsychologyPsychology 28802880 722722 80%80% 20%20%

   Enrollment Enrollment

Count Count Enrollment Enrollment

Percent Percent

TopnameTopname

GavilaGavilan n

Not Not GavilaGavila

n n

GavilaGavila

n n

Not Not Gav Gav

Biological Biological SciencesSciences 40634063 905905 82%82% 18%18%

Fine and Fine and Applied ArtsApplied Arts 90159015 19501950 82%82% 18%18%

Business and Business and ManagementManagement 93479347 16421642 85%85% 15%15%

InterdisciplinarInterdisciplinary Studiesy Studies 2902529025 33803380 90%90% 10%10%

Commercial Commercial ServicesServices 44834483 6565 99%99% 1%1%

Environmental Environmental Sciences and Sciences and Technologies Technologies (new)(new)

00 00 0%0% 0%0%

Modeling FlowModeling Flow Time (3 successive Fall terms)Time (3 successive Fall terms) Latitude Latitude TOP code TOP code Term length (short vs. full term)Term length (short vs. full term) Course UnitsCourse Units Degree ApplicabilityDegree Applicability TransferabilityTransferability Basic Skills StatusBasic Skills Status Meeting DaysMeeting Days AgeAge GenderGender EthnicityEthnicity SuccessSuccess Cumulative Units Attempted (student Cumulative Units Attempted (student

experience)experience) Educational LevelEducational Level

Logistic RegressionLogistic Regression

Entered all variables with no interactions Entered all variables with no interactions except meeting days due to large amount except meeting days due to large amount of missing dataof missing data

Only time not significantOnly time not significant Findings seemed to reinforce univariatesFindings seemed to reinforce univariates Risk = .175 (guessing = .25 in this case), Risk = .175 (guessing = .25 in this case),

Hosmer and Lemeshow < 0.0005, Cox & Hosmer and Lemeshow < 0.0005, Cox & Snell R-square = 0.228, Nagelkerke R-Snell R-square = 0.228, Nagelkerke R-square = 0.343, n = 123,882square = 0.343, n = 123,882

CARTCART In general, those taking non-transferable vocational In general, those taking non-transferable vocational

courses were more likely to attend another college. courses were more likely to attend another college. If taking general education/transfer courses those:If taking general education/transfer courses those:

north of Morgan Hill very likely to attend another north of Morgan Hill very likely to attend another collegecollege

south of Morgan Hill very likely to attend Gavilan south of Morgan Hill very likely to attend Gavilan Those in the Morgan Hill area very likely to attend Those in the Morgan Hill area very likely to attend

Gavilan if: Gavilan if: TOP code was Biological Sciences, Business and TOP code was Biological Sciences, Business and

Management, Information Technology, Fine and Management, Information Technology, Fine and Applied Arts, Commercial Services, or Applied Arts, Commercial Services, or Interdisciplinary Studies (basic skills and tutoring) Interdisciplinary Studies (basic skills and tutoring) OR OR

TOP code was Media and Communication, TOP code was Media and Communication, Education, Foreign Language, Health, Family and Education, Foreign Language, Health, Family and Consumer Sciences, Humanities, Mathematics, Consumer Sciences, Humanities, Mathematics, Physical Sciences, Psychology, or Social Sciences Physical Sciences, Psychology, or Social Sciences AND those courses were degree applicable AND those courses were degree applicable (otherwise attend elsewhere)(otherwise attend elsewhere)

Risk = .16, n = 147,139Risk = .16, n = 147,139

Chose not to attend GavilanChose not to attend Gavilan Chose to attend GavilanChose to attend Gavilan

Choice Factor Choice Factor (sorted by (sorted by mean)mean) MeanMean sdsd

Choice Factor Choice Factor (sorted by (sorted by mean)mean) MeanMean sdsd

Quality Quality instruction instruction and servicesand services 6.46.4 1.11.1

Cost of Cost of attending attending (tuition, (tuition, books, books, housing)housing) 6.06.0 1.41.4

Going to a Going to a college with a college with a good good reputationreputation 5.95.9 1.31.3

College staff College staff who are who are welcoming welcoming and friendly and friendly 5.95.9 1.41.4

College staff College staff who are who are welcoming welcoming and friendlyand friendly 5.95.9 1.31.3

Quality Quality instruction instruction and servicesand services 5.75.7 1.71.7

Having a new Having a new environment environment with new with new peoplepeople 5.15.1 1.61.6

Going to a Going to a college with a college with a good good reputationreputation 5.35.3 1.71.7

Next StepsNext Steps Have faculty and administration assist Have faculty and administration assist

with interpretation in the context of the with interpretation in the context of the possible possible

Use data to create “competitive” Use data to create “competitive” strategies to improve our programs, strategies to improve our programs, services, and imageservices, and image

More Data!!!More Data!!! Obtain more relevant variablesObtain more relevant variables Conduct improved survey of out flowersConduct improved survey of out flowers Continue to track flowContinue to track flow

Improve statistical modelsImprove statistical models

Limited Domain of Limited Domain of ComparisonComparison

In comparing student movers or In comparing student movers or stayers within the CCC system, we stayers within the CCC system, we miss two sources of “leakage” that miss two sources of “leakage” that could inform strategycould inform strategy Providers outside of the CCC systemProviders outside of the CCC system Students who drop out because of Students who drop out because of

unmet needs at a district but who unmet needs at a district but who cannot find an alternative.cannot find an alternative.

Zip Code LimitationsZip Code Limitations

Reliability of data must be checked.Reliability of data must be checked. Zip codes are relevant for entities Zip codes are relevant for entities

with clear borders—only true of with clear borders—only true of districts and of single-college districts and of single-college districts.districts.

They serve as an “auxiliary” variable; They serve as an “auxiliary” variable; other variables are needed to draw other variables are needed to draw meaningful conclusions.meaningful conclusions.

Distance learning changes traditional Distance learning changes traditional view.view.

Contact InformationContact Information Willard HomWillard Hom whom@cccco.eduwhom@cccco.edu (916) 327-5887(916) 327-5887

System Office, System Office, California Community California Community CollegesColleges1102 Q St.1102 Q St.Sacramento, CA Sacramento, CA 95815-651195815-6511

Terrence WillettTerrence Willett twillett@gavilan.edutwillett@gavilan.edu (408) 848-4852(408) 848-4852

Gavilan Community Gavilan Community College College 5055 Santa Teresa 5055 Santa Teresa BlvdBlvdGilroy, CA 95020Gilroy, CA 95020